Within the NTDU group, we continue to utilize a number of automated, medium throughput cell-based assays to screen small compound collections against rat mixed cortical cultures, human neural stem cells (NSC) and human NSC-derived neurons and astrocytes. We've utilized live cell imaging based assays with human neurons, as well as developed fluorescence-based assays to probe high content imaging endpoints. These cell based screening assays, in 384 well plate format, have been successfully employed in multiple screens with multiple investigators. We have continued to generate new chemical tool compounds in our chemistry labs to facilitate screening and mechanistic studies in our research projects. We continue to produce and purify a number of recombinant proteins, such as HIV Tat protein for our own studies and provide that Tat protein to extramural researchers. With the Section of Infections of the Nervous System (SINS), we have continued to work on multiple research projects. We continue to characterize the neurotoxicity resulting from the expression of the HERV-K env protein in NSC and human neurons, and have already identified some compounds and proteins which attenuate HERVK env mediated neurotoxicity. Exogenously added recombinant HERV-K Env protein also elicits significant neurotoxicity. Microelectrode array electrophysiologic studies have provided a functional endpoint to these studies. We have characterized the toxic actions of Zika virus on neural cells, and by selective screening, have identified some compounds which may block the Zika virus-dependent neurotoxicity. The HIV Tat antagonist program has incorporated direct label-free binding assays, including protein thermal shift assays, as well as Tat-dependent selective LTR activation assays to complete the screening of more than 2000 compounds to identify new lead Tat inhibitors. The resultant hit compounds continue to be characterized for potency and biopharmaceutical properties, as well as activity against HIV viral replication. The NTDU has continued a number of studies in collaboration with other intramural investigators. We continue to work with Dr. Harish Pant and his research team to characterize the neuroprotective actions of the Cdk5 modulator TFP-5 against multiple toxic insults. Likewise, we continue to work with the Sibley research group to characterize the dopamine D3 receptor modulators that they have identified, using our live cell imaging platforms for quantitative analysis. We continue working with three clinical investigators, Drs. Kareem Zaghloul, Prashant Chittiboina and Peter Williamson on new research projects with their respective laboratories. We are working with Dr. Robert Innis and his group to characterize the ligand-receptor binding interactions of new PET ligands. We continue to work closely with the Dr. Francis McMahon laboratory to generate fluorescently labeled NSC and neuronal cultures from control and neuropsychiatric patients, to characterize their morphologic changes in response to stressors or toxic challenges. We also work with the Clore Laboratory to characterize the neurotoxicity of A42 peptides and attenuate their neurotoxic actions both morphologically and electrophysiologically with small molecules and proteins. We have characterized the neuronal growth and development of human iPSC-derived neurons with the laboratory of Dr. Michael Ward. We have initiated a drug screening initiative to characterize multiple individual neuronal populations with selective protein knockouts in order to more fully characterize their role(s) in neurodegenerative disorders. Cell line generation NeuroTherapeutics Develeopment Unit (NTDU) As part of its role in facilitating translational research the NTDU develops cell lines in human neural stem cells (NSCs) for both internal and collaborative use. Lines have been developed to ubiquitously express the tdTomato fluorescent protein to aid in conducting screening assays. Collaborations between the NTDU and intramural and extramural groups has led to the development of more than ten such NSC lines that will make it possible to conduct medium throughput screens aimed at targeting several neurological diseases including bipolar disorder and Alzheimers diseases. Additionally, the NTDU has also generated additional cell specific lines for internal use that are also available to collaborators. These lines use cell specific promoters to express tdTomato in neurons and astrocytes and could have also have broad utility for conducting screens in distinct neural cells.